Apocalypse Guardian
by DragonSiren7
Summary: There were supernatural forces at work in Domino City long before Yuugi ever solved the puzzle. Seto Kaiba was always meant to have a twin, but when she is stillborn, Fate intervenes. With her soul split into the three Centurion items, will she ever be able to reunite with her brother, and when she does, can she change her brother's destiny, and protect him from destruction?


**AN: **Hi everyone! This is my first YuGiOh fanfic, and there is a major OC. I promise, she isn't a Mary Sue! Please, just give this story a chance! Seto is the main character, and Alyx, the OC, only really comes in as a character developer... and gets to torture Gozaburo, because admit it, we all hate his guts. Mokuba is the main character after Seto, then Akyx is tied with Yugi and the gang. She is pretty active in this chapter, simply because I'm setting her up. She fades in importance as the story goes on, but will remain to kick butt for her brothers - Seto and Mokuba. More information is at the end of CMthe chapter!

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><p><strong>DISCLAIMER: Am I a millionaire? No? Am I older than 15? No? Am I out of high school? No? Then I must not own YuGiOh!<strong>

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><p><strong>PROLOGUE<strong>

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><p>Blue eyes darkened by life watched a young boy with wild black hair skip through the crowds, laughing at every little thing. Despite himself, Seto felt a small smile settle on his face at the sight of his laughing and smiling little brother.<p>

"Look, Nii-sama*!" cried Mokuba, pointing at a long line of people and bright advertisements. Camera crews were milling around, and crowds were gathered around colorful posters. "Rare Centurion Item and a million dollars prize money!" continued Mokuba. That, if nothing else, captured Seto Yagami's attention. A million dollars could go a long way, and for orphans with no hope of other income for years, it could be a miraculous snatch.

"The legend of the Items: it is said that every person whom has tried on the Centurion Shield, one of three centurion items, Roman/Egyptian equivalent to the seven Egyptian Millennium Items, has fallen into a coma and never awoken after just five minutes. If you can put on this necklace and stay awake and aware without falling unconscious for a full six minutes, then the necklace and a million dollars will be your prize. Funded by Industrial Illusions CEO, Crawford J. Pegasus," read Seto.

"Nii-sama, it sounds dangerous." Mokuba's emerald eyes were wide s he watched a groaning and semi-conscious man be lifted on a stretcher and carried away.

"Tch. I don't believe in all this occult crap. These people are probably all paid to act like this." The brown haired boy picked up pen hanging next to a clipboard, and signed on the volunteer list, _Yagami Seto._

"Are you really going to do this, Nii-sama?"

"Hai, Mokie. Even if it is all a scam and they try to pay me to act like this, I can just say no and grab the million bucks anyway. And if the deal's better to go along with the scam, then that's what I'll do."

"Ni-sama..." Mokuba trailed off and moved closer to his big brother, clutching the older boy's hand nervously. Eventually they reached the front of the line, where a man with dark sunglasses and slicked back, black hair waited by a half gold, half silver necklace resting on a suit case.

"Where are your guardians, kid?" questioned the suited man.

"Domino City Cemetery, buried under the willow tree sixteen paces from the church." When asked a question, Seto always replied with the truth, he simply made it as detailed or as simple as he felt was called for.

If he could throw this man off balance, then longer was better.

The man - whom happened to be named Croquet - blinked once, twice, shocked by such an answer spoken in that strange half sarcastic, 1/4 flippant, and 1/4 deadpan tone from someone other than his eccentric master. Taking advantage of Croquet's momentary shock, Seto used his hidden speed to his advantage and snatched the necklace, slipping it on in the same movement.

"Don't!" cried Croquet, grabbing for the medallion. The gold and silver flashed, burning the man's hand and lighting up the street. When the light was gone, a girl with brown, we goth length hair and and azure eyes was gripping the silver half of the shield medallion, the gold half now hung on a pure gold cord and rested on Seto's chest.

"Who are you?" demanded Croquet. The girl did not reply, simply continued staring at the shocked brothers.

"The time is up, is it not?" she whispered, her voice rising and falling like waves crashing on rocks in the silence of night.

"What are you taking about? It's been a minute, at most -" Croquet's voice died in his throat at the blinking "6:00" on the timer.

"Alexandra. You look like Alexandra would have," whispered Seto finally, staring wide eyed at the girl who looked exactly like him.

"Brother," smirked the girl in reply, before pausing and glancing at the black haired boy hiding behind the brunette. "Brothers," she amended. Seto suddenly growled, backing up as far as the gold chain would allow.

"I don't believe in all this occult stuff. Cut it out and tell me who you really are and what is going on." Seto's eyes flashed in determination and anger - family was the most important thing to him, dead or alive.

"I see," replied the girl flatly, before lifting the silver half of the necklace off Seto and hanging it around Mokuba's neck before the elder even had time to blink. "In that case, I am a hologram created from the Centurion Shield, which has been tampered with by the CEO of Industrial Illusions. My purpose is to protect the wearers of the necklace."

Seto nodded - that, at least, had a scientific explanation. The girl smiled sadly, and bowed her head. "You may refer to me as Alyx, if you wish. And yes, I am very much sentient. I am Industrial Illusions one - and quiet possibly only one ever - working AI, artificial intelligence. If you ever need me, simply call - mentally or physically, it matters not."

The girl faded from existence, still smiling sadly.

"I see. Interesting. This is the million dollars, is it not?" stated the nine year old boy, already clicking the silver briefcase packed with cash shut.

"Wait, something's going on. Industrial Illusions did not -!"

"Come, Mokuba," ordered the brunette, striding off with his sapphire eyes fixed straight ahead. "We don't have time for this. It's about time we set you up with a savings account."

"Wait for me, Nii-sama! Don't we need a security number and all that stuff to get a bank account?" the young boy's voice was fading as the duo left, one with the stalking, purposeful gaze of a predator, and one the normal, skipping pace of a young boy.

"Leave that to me, Bocchan." Croquet could barely make out the reply, but he could still see the stride of the girl that had reappeared. It was the stride of someone who walked lightly, on the balls of their feet, prepared to break into a sprint at a moments notice, arms slightly away from the body, prepared to grab or strike in equal measure. It was the stride of a warrior - the stride of a bodyguard, a guardian. Croquet recognized it as a version of his own.

"Master," the man turned to the shadows. "Now what?"

"Now, Croquet," came the wavering, rolling, part sarcastic, part deadpan, and part flippant voice, "we wait and we observe." Gold glinted from behind a curtain of silver. "You know as well as I that Alyx-girl is no hologram, nor an AI. I expect things to be interesting, these coming years. Come, it's time to go back to America. We are done here."

"Of course, Master Crawford."

And the black clad bodyguard followed the red wearing master down the black roads, leaving the crowds of people behind.

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><p>The Yagami brothers were standing exactly four feet from the dark brown wood of the counter at the Domino City Bank, watching Alyx "work her magic" and fill out all the forms continuously appearing before her, occasionally calling them over to sign something, then shooing them away again.<p>

"Nii-sama?" questioned Mokuba suddenly, as the black haired, recently four year old boy turned to his older, almost ten year old brother. (**AN**: I hate doing this, so I'll make it quick. I don't care what the ages are SUPPOSED to be, this is how they will be. Gozaburo Kaiba will adopt them next chapter, on Seto's 10th b-day. If that is not right - cause I honestly don't know - then deal with it.)

"Yes, Mokie?" prompted Seto, when the younger seemed to fall back into a thoughtful silence.

"Halowgraphs..."

"Holographs, Mokie."

"Right. Sorry, Nii-sama. But, holographs... They're... made of light, aren't they? And... Alyx... is one?"

"Yes, Mokuba. What are you thinking so strongly about?"

"Well, if she's made up of light... How can she fill out the papers and touch stuff?"

Seto paused, eyes widening as he glanced between Alyx and his curious little brother. It was unlike him to miss something so obvious. Had he purposefully ignored the impossibility of it all, simply because he _wanted_ her to be a holograph, due to it being the simplest answer? The brunette girl turned and smiled, as if she knew what they were talking about. She winked, and both boys could swear they heard a whispered "magic" in the back of their heads.

"Nii-sama... she didn't open her mouth, but I heard her," whispered Mokuba, tugging down on his elder brother's sleeve. The sapphire eyed boy nodded and kneeled next to his shorter brother, so their heights were about even.

"So did I, Mokie."

"Could what she said... Could magic be real?"

"I don't know, little brother - but no matter what, I'll always protect you."

The silver flashed warningly, and the gold gleamed dangerously as the two matching necklaces swayed slightly. Azure eyes widened as they stared at paperwork, only half focusing on the black typed words while the rest of her attention focused on her brothers and a small sliver of her personal brand of technomagic altered the data in the bank's - and all other's - systems.

If anyone _ever _tried to hurt _either_ of her brothers, they better pray she is dead by then. And seeing as she already died once, and has survived the 3,000 years since she was sent to the past to be imprisoned in the Centurion Shield, the death of Alexandra Yagami is an impossible nightmare.

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><p><strong>AN: <strong>Hello again, it's your authoress speaking! So, below this information spreeis a **_PROPHECY_** which is _supposed_ to be at the top of the page, but won't obey my iPad's commands. *sigh* Anyway, even if you skip the spoilers - which will all be explained late - please scroll down to read the prophecy thingy and review (^_-)!

Summary:

There were supernatural forces at work in Domino City long before Yuugi ever solved the puzzle, Ryou Bakura moved in, and Malik so much as tu pouched the Millenium Rod. Seto Kaiba was always meant to have a twin, but when she is stillborn, Fate intervenes. With her soul split into the three Centurion items, will she ever be able to reunite with her brother, and when she does, can she change her brother's destiny, and protect him from destruction?

**Main Chars:**

Kaiba Meaning of Name: Seahorse

**_Seto Kaiba_**

Meaning of Name: White OR violence, turmoil, etc.

Eye Color: Sapphire Blue

Hair Color Brown

Height: 6' 4"

Age: 14

Signature: Blue Eyes White Dragon

Deck: Saga of the Blue Eyes White Dragon

**_Mokuba Kaiba_**

Meaning of Name: Wooden Horse (relation to Trojan Horse?)

Eye Color: Cobalt

Hair Color: Black

Height: 4' 7"

Age: 10

Signature: Sword Stalker of Vengeance

Deck: Reptile Destruction

**_Alexandra "Alyx" Kaiba_ **

Name meaning: Defender of Mankind

Eye Color: Azure Blue

Hair Color: was brown, now is silver due to Centurion item's influence

Height: 6' 2"

Age: 14

Signature: Azure Eyes Silver Dragon and Belial - Marquis of Darkness

Deck: Saga of the Dragon Guardian of Destruction

**SPOILERS/INFO:** She was born the twin sister of Seto Kaiba, but died exactly a minute after her brother was born due to a nurse's ineptitude. This was not meant to happen, so Alyx's soul was placed somewhere she could help her brother and meet him. In the "original series," the three Centurion items were never discovered, meaning Alyx's soul could never enter the physical world, and Pegasus never found any of the Centurion Items (he believes the entire thing is the Centurion Shield, while really, it is all three of the Centurion Items combined.) However, in this series, Alyx developed a Yami over time due to overexposure to the Shadow Realm and one of the spirits inside - Alexandra, twin sister of High Pries Seth and ancestor of Alexander the Great, along with Seto, Mokuba, and Alyx - short for Alexandra.

Alexandra helped Alyx gather all three of the Centurion Items and melded them together - the gold halves of the Ring of Apophis and Centurion shield, with the silver half of the eye of Horus, and vice versa. (**AN**: Imagine the Ring of Apophis like the Millenium Ring, but without the tassels, then a shield like the ones used in Ancient Rome (so circular) , and the eye like the ones on the Millenium Items.)

Seto was drawn to the contest not only by the million dollars reward money, but because the other half of his soul - Alyx - was calling out to him, he is just too obstinate to admit it. MORE DETAILS LATER.

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><p><strong>To counter the power of a thousand years<strong>

**Ancient Roman and Egyptian magic combined **

**To form us items three. **

**The powers of the Century. **

**Gather all three and you will see **

**The paths to alter reality. **

**A Yami no Game **

**A Shadow Game**

**The Dragon has left through the door of Darkness,**

**And now has the key to open it**

**Will you enter?**


End file.
